Weird structures near Earth’s core may be scars from a primordial interplanetary collision
A group of mysterious, ultradense structures just outside Earth’s core may be the remnants of an ancient interplanetary collision, new research suggests. These strange structures are known as ultralow-velocity zones (ULVZs), because seismic waves generated by earthquakes travel about 50% more slowly through these zones than through the surrounding mantle. That means the ULVZs are … Read more